[jtbigwoo]

Counter offers have a really low success rate in my experience. That person has already weighed the pros and cons of staying and decided to leave. It won't take much to push them to leave again.

In addition, everybody else in the company now has an incentive to look for a new job themselves since they see a short cut to get a raise.

Better to keep people happy by offering market-rate salaries in the first place.